Move build-types config into own module (#50450)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/50450

Intends to be reused by the incoming `buildApiSnapshot` behaviour.

Changelog: [Internal]

Reviewed By: iwoplaza

Differential Revision: D72306509

fbshipit-source-id: 9e03c95f2469e10c05bdd0be39d4e217a6cc197f

scripts/build-types/buildGeneratedTypes.js

@@ -10,6 +10,7 @@
  */
 
 const {PACKAGES_DIR, REPO_ROOT} = require('../consts');
+const {ENTRY_POINT, IGNORE_PATTERNS, TYPES_OUTPUT_DIR} = require('./config');
 const getRequireStack = require('./resolution/getRequireStack');
 const translatedModuleTemplate = require('./templates/translatedModule.d.ts-template');
 const translateSourceFile = require('./translateSourceFile');
@@ -17,15 +18,6 @@ const {promises: fs} = require('fs');
 const micromatch = require('micromatch');
 const path = require('path');
 
-const OUTPUT_DIR = 'types_generated';
-
-const IGNORE_PATTERNS = [
-  '**/__{tests,mocks,fixtures,flowtests}__/**',
-  '**/*.{macos,windows}.js',
-];
-
-const ENTRY_POINTS = ['packages/react-native/index.js.flow'];
-
 /**
  * Build generated TypeScript types for react-native.
  *
@@ -37,9 +29,7 @@ const ENTRY_POINTS = ['packages/react-native/index.js.flow'];
  * along with our own pre and post-processing.
  */
 async function buildGeneratedTypes(): Promise<void> {
-  const files = new Set<string>(
-    ENTRY_POINTS.map(file => path.join(REPO_ROOT, file)),
-  );
+  const files = new Set<string>([path.join(REPO_ROOT, ENTRY_POINT)]);
   const translatedFiles = new Set<string>();
   const dependencyEdges: DependencyEdges = [];
   const allErrors: Array<ModuleTranslationError> = [];
@@ -67,7 +57,7 @@ async function buildGeneratedTypes(): Promise<void> {
 
   await fs.copyFile(
     path.join(__dirname, 'templates/tsconfig.json'),
-    path.join(PACKAGES_DIR, 'react-native', OUTPUT_DIR, 'tsconfig.json'),
+    path.join(PACKAGES_DIR, 'react-native', TYPES_OUTPUT_DIR, 'tsconfig.json'),
   );
 
   if (allErrors.length > 0) {
@@ -133,7 +123,7 @@ function getBuildPath(file: string): string {
   return path.join(
     packageDir,
     file
-      .replace(packageDir, OUTPUT_DIR)
+      .replace(packageDir, TYPES_OUTPUT_DIR)
       .replace(/\.js\.flow$/, '.js')
       .replace(/\.js$/, '.d.ts'),
   );

scripts/build-types/config.js

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ * @oncall react_native
+ */
+
+/**
+ * The root entry point for type generation (main entry point for the
+ * react-native package).
+ */
+const ENTRY_POINT = 'packages/react-native/index.js.flow';
+
+/**
+ * Ignore patterns for source files that should not be considered for
+ * translation.
+ */
+const IGNORE_PATTERNS = [
+  '**/__{tests,mocks,fixtures,flowtests}__/**',
+  '**/*.{macos,windows}.js',
+];
+
+/**
+ * The output directory name for generated type definitions in each translated
+ * package.
+ */
+const TYPES_OUTPUT_DIR = 'types_generated';
+
+module.exports = {
+  ENTRY_POINT,
+  IGNORE_PATTERNS,
+  TYPES_OUTPUT_DIR,
+};